Segment Information and Major Customers - Summary of Net Revenue for Groups of Similar Products and Services (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jul. 25, 2020	Apr. 25, 2020	Jan. 25, 2020	Oct. 26, 2019	Jul. 27, 2019	Apr. 27, 2019	Jan. 26, 2019	Oct. 27, 2018	Jul. 25, 2020	Jul. 27, 2019	Jul. 28, 2018
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue	$ 12,154	$ 11,983	$ 12,005	$ 13,159	$ 13,428	$ 12,958	$ 12,446	$ 13,072	$ 49,301	$ 51,904	$ 49,330
Disposed of by sale | SPVSS Business
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue										168	903
Product
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									35,978	39,005	36,709
Infrastructure Platforms
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									27,122	30,099	28,286
Applications
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									5,568	5,803	5,036
Security
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									3,154	2,821	2,388
Other Products
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									135	281	999
Service
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenue									$ 13,323	$ 12,899	$ 12,621